Lively but exasperating, “The Institute” blurs the line between straight documentary and pure fiction. It’s hard to tell where authenticity ends and an alternative reality begins.

In fairness, that’s the point of director Spencer McCall’s approach.

Playing mind games with the audience is a reflection of the film’s subject: an urban adventure, set in California’s Bay Area, created by several artists to engage the public in mystery and wonder.

Somewhat reminiscent of David Fincher’s 1997 puzzler “The Game,” “The Institute” concerns the now-defunct Jejune Institute, created by Jeff Hull. Several years ago, fliers instructed San Franciscans to call a phone number, which in turn gave the curious an address for the organization in the city’s financial district.

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People who showed up were induced to explore quirky little discoveries around town, dance on the street and learn about two compelling individuals — one a 1970s-style, consciousness-raising guru and the other a young woman, Eva, who disappeared in 1988. McCall films a search through underground tunnels looking for a man who allegedly vanished while looking for Eva.

The extent of the Jejune Institute’s elaborate production is remarkable, and past participants who recall their experiences on camera seem to have been profoundly moved by surrendering themselves to a remote, guiding hand.

The problem here is that McCall expects “The Institute’s” audience to yield as well. A viewer is dropped down a rabbit hole of made-up nonsense mixed with truth, but distinguishing one from the other isn’t always obvious.

If you’re in the mood to be fooled, then fine. But if you’re genuinely curious about the phenomenon Hull and his allies pulled off — and why it mattered to some people — you might find your involuntary compliance gets in the way.

Tom Keogh: